Ultraviolet Morphology and Star Formation in the Tidal Tails of NGC 4038/39

We present Galaxy Evolution Explorer far-ultraviolet (1530 Å) and near-ultraviolet (2310 Å) observations of the archetypal merging system NGC 4038/39, "the Antennae." Both tails are relatively bright in the UV, especially in the vicinity of the tidal dwarf galaxy candidates at the end of the southern tail. The UV light generally falls within the optically delineated tails, although the UV light is considerably more structured, with a remarkably similar morphology to the tidal H I. The UV colors suggest that there has been continuing star formation within the tidal tails, even outside the previously studied tidal dwarf regions. Within the inner disk regions, there are interesting UV features that appear to be related to the extended soft X-ray loops and halo recently discovered by Chandra .